Microsporidia are ubiquitous causing infections in insects, fish, and mammals. Recently microsporidia have been demonstrated to infect man. These organisms cause ophthalmic and gastrointestinal infections primarily in patients with AIDS. Several genera of human pathogens have been cultivated in cell culture. Presently there is no data regarding the ability of these organisms to survive under various environmental conditions. Also, there are no reports regarding the effects of disinfectants on microsporidial spores. The survival of microsporidial spore after exposure to disinfectants such as chlorine, alcohol, and quaternary ammonium compounds and environmental conditions such as temperature and desiccation will be studied. Cultivation of microsporidia in the shell vial system using various cell lines has been investigated and microsporidia appear to replicate in both fibroblast and epithelial cell lines. Staining methods are being evaluated to detect microsporidial inclusions in infected cells. A method for quantitation of microsporidial DNA will be evaluated for its ability to detect microsporidial growth after exposure to disinfectants and environmental conditions.